Catheters have been used for many years to remove body fluids, whereby a sharp pointed instrument is fitted with a cannula and used to insert the cannula into a body cavity as a drainage outlet. Trocar catheters are used for evacuation of fluid, blood and air from the pleural space. Interpleural irrigation is one technique used following thoracotomy to reduce cough and sign reflexes.
This is a common practice of placing an intake into a body cavity of a patient and to place the tube in communication with a vacuum source to drain fluids from the cavity. The vacuum may be a manually operated syringe but more commonly is a wall outlet of a vacuum system if that is available. One such device is shown in Friend U.S. Pat. No. 3,982,546 in which a reservoir is used in communication with passages to accumulate fluids, particularly the bladder in this case. This patent is intended to prevent discharge of drainage fluid without releasing the fluid to the environment when normal discharge is interrupted. A special reservoir is used for this purpose.
Another design which employs a second lumen is shown in Sheridan U.S. Pat. No. 3,599,641. This design does not employ a stylette and is not open on the distal end. It has no injection port for secondary treatment and employs a single molded part. This patent is designed to have quick and sterile connections for multiple purposes. While these designs are useful in surgical procedures, such designs have not met with commercial success in some uses because of the difficulty of precisely inserting and locating the catheter.
Allen U.S. Pat. No. 4,810,244 discloses an improved trocar having plural cannula for washing and draining under microscopic observation. It is specifically designed for extremely small procedures, usually under microscopic observation, whereby two cannula are connected so that wash fluids may be added by one and removed by the other to provide a continuous circuit of fluid flow. The particular procedure which is of interest in Allen is extraction of oocyctes from follicles in human ovaries, and the device uses inner and outer cannula so that the inner cannula can penetrate the follicle being drained. The outer ends of the cannula are connected.
Other catheter devices which are used in the medical field are shown in: Roberts U.S. Pat. No. 3,459,188 for abdominal use; Gay et al U.S. Pat. No. 5,047,018 for heart procedures; Rudie U.S. Pat. No. 3,804,097 for abscess treatment; and Kopp U.S. Pat. No. 4,073,297 for arterial and vein insertion.
None of the prior art designs are directed at the very serious problems incurred in pleural surgery where large quantities of fluids, blood and air are to be removed from patients of various ages and sizes. The discomfort and pain caused by loss of vacuum at any time can seriously affect procedures being performed on the patient. Nevertheless, there is often a need to give pain relief just at the time when vacuum is most needed. Also, antibiotic treatment is often performed simultaneously with evacuation of fluids, sometimes requiring two catheters to be inserted if treatment cannot be given by syringe. Here particularly, direct application at the point of need is not possible using a syringe.
Accordingly, it is an object of the present invention to provide a safe and simple method to apply vacuum to pleural cavities.
Another object of this invention is to provide a device which is suitable for simultaneous evacuation and irrigation of the interior pleural region of the body without additional discomfort and without interference with either procedure.
Yet another object of the present invention is to provide a device capable of locally administering drugs and pain relief at a point of need while that region is being evacuated by vacuum.
Other objects will appear hereinafter.